Louis-Christophe Zaleski-Zamenhof (born Ludwik Zamenhof; 23 January 1925 – 9 October 2019) was a Polish-born French civil and marine engineer, specializing in the design of structural steel and concrete construction. He was a grandson of the Polish Jewish L. L. Zamenhof, the inventor of the international auxiliary language Esperanto. From the 1960s until his death, Zaleski-Zamenhof lived in France.
Zamenhof was born in Warsaw, to a Jewish family. After his father Adam Zamenhof was arrested and shot to death by the Nazis occupying Poland, he and his mother, Wanda (Frenkiel), barely escaped deportation to the Nazi death camp at Treblinka where his aunts, pediatrician Zofia Zamenhof and writer Lidia Zamenhof, were murdered. The teenager remained in hiding within Poland under the false name of 'Krzysztof Zaleski', a name he maintained afterwards in remembrance of the ordeal.
During that time, he worked in a tomato field together with a Pole who happened to speak Esperanto; this person once tried to recruit him to the cause, asking him: Ĉu vi konas Esperanton? ("Do you know Esperanto?"). 'Christoph' blurted out: Ho jes, mi konas; ĝin inventis mia avo! ("Oh yes, I know it; my grandfather invented it!") He immediately feared that he had been indiscreet and would be denounced and arrested, but nothing untoward occurred.
After earning a doctorate in civil and marine engineering, he began work as a professional engineer. Beginning in Poland after World War II and since the 1960s in France, he has designed precast concrete structures and projects ranging from deep-sea oil rigs, sports complexes, and the Charles de Gaulle Memorial, which dominates the village of Colombey-les-Deux-Églises. He has also taught the theory and techniques of land and sea construction at various academic institutions.
On 14 April 1999 Hanna Konopka, president of the Zamenhof Foundation of Białystok, announced that Pope John Paul II would be the first recipient of the Foundation's Tolerance Medal (Medalo de Toleremo).